Council chiefs have also warned not all the necessary work can be done during school holidays, raising the prospect of some pupils having to move to temporary accommodation in term time.
Other council buildings in poor condition include the City Chambers, Central Library and eight community centres.
The warning comes after 17 Edinburgh schools built under public private partnership agreements were suddenly closed in April 2016 after a contractor warned of structural defects.
A new council report admits investment in maintenance of council property has been allowed to decline steadily over the past two decades.
It identifies a backlog of £153 million worth of work to be done to schools, libraries, community centres, offices, depots and other buildings.
And it warns of “significant health and safety implications” if the backlog is not tackled.
Finance convener Alasdair Rankin pledged more money would be allocated to deal with the problem and said top priority would be given to making sure buildings were safe, and wind and water tight.
A survey of the council’s property estate at the end of last year found that out of 560 operational buildings, 480 were in category A or B – “good” or “satisfactory”. But 71 were in category C – “poor, showing major defects and/or not operating adequately”. And nine were in category D – “bad, economic life expired and/or risk of failure”.
The report says a total of £36.6m capital spending should be spent in 2018/19 based on the condition survey, but adds that the time needed to mobilise designs and secure consents means less than half of that – £18m – is likely to be feasible.
And it warns the council must introduce a planned maintenance programme for the long term.
“New buildings with more sophisticated mechanical and electrical systems, particularly in the schools’ estate, will very quickly deteriorate if this remains unaddressed,” the report says. Cllr Rankin said he wanted to see schools and community centres removed from the worst categories.
“They will be towards the top of the priority list,” he said. “When it comes to school buildings, all the necessary work cannot be done during holiday times. There might be temporary measures put in place to minimise disruption. It might mean children going, on a temporary basis, to another school or using some temporary accommodation.”
In other cases, a rolling programme would allow pupils to move to another part of the same building while work is carried out.
He said the council’s failure to have a planned maintenance programme was “entirely wrong”.
And he said he hoped to invest more in the first year than the £18m proposed in the report, adding: “What we are looking to do as a coalition is see if we can find the capacity to spend more than that so we get the first year off to a good start.
“The primary concern is health and safety and making sure buildings are wind and water tight. These sorts of remedial works will be the top priority.”
Tory councillor Andrew Johnson said the poor state of the council’s property was “a ticking time bomb”.
He said: “Given what has happened in Edinburgh in recent years we have to take this very seriously.” An existing capital programme for building upgrades of £14m a year will contribute £70m to the cost of work needed, but that still leaves an £83.5m shortfall – £34m revenue and £49m capital.
The report shows the maintenance required includes £16.7m on roofs, £10m on floors and stairs, £15m on redecorations, £5.8m on ceilings, £18.6m on external walls, windows and doors, and £31.2m on electrical services.
Green finance spokesperson Gavin Corbett said: “Over the last 40 or 50 years, or maybe even longer, too much attention has been paid to big new build or refurbished buildings and too little to the less glamorous tasks of routine maintenance. But, as anyone who owns a property will know, if you cut back on maintenance today, it will increase your bills tomorrow.
“It’s time to call a halt to that way of thinking. The council has been right to invest in a major survey of its schools, libraries, community centres and other public buildings. So the question now is what to do about the £49m gap to fund improvements needed in the next five years, or the £34m gap in maintenance budgets. The scale of funding needed exposes how little freedom the council has to invest properly in public buildings with council tax capped, business rates out of council control and new powers like a tourism levy being denied to Edinburgh. Our capital can have the public buildings it needs if the will to invest is matched by the power to do so.”